A playlist timeout was resumed in the same session, but hls.js reloads no manifest on startLoad: no
request, no error, a spinner for good. It is now asked for again like a server away. An absence
also ended only on a fragment, which native HLS never reports, and a viewer trying again after the
error started with the spent window; both now start a fresh one. The slow-connection meter was
reset only when hls.js was built, so a direct answer showed the previous stream's numbers, and a
replaced session's late fragment still counted; its rates now use the stats overlay's units.